src/test/txrequest_tests.cpp

git / moonbite-core / src/test/txrequest_tests.cpp · raw
// Copyright (c) 2020 The Bitcoin Core developers// Distributed under the MIT software license, see the accompanying// file COPYING or http://www.opensource.org/licenses/mit-license.php.#include <txrequest.h>#include <uint256.h>#include <test/util/setup_common.h>#include <algorithm>#include <functional>#include <vector>#include <boost/test/unit_test.hpp>BOOST_FIXTURE_TEST_SUITE(txrequest_tests, BasicTestingSetup)namespace {constexpr std::chrono::microseconds MIN_TIME = std::chrono::microseconds::min();constexpr std::chrono::microseconds MAX_TIME = std::chrono::microseconds::max();constexpr std::chrono::microseconds MICROSECOND = std::chrono::microseconds{1};constexpr std::chrono::microseconds NO_TIME = std::chrono::microseconds{0};/** An Action is a function to call at a particular (simulated) timestamp. */using Action = std::pair<std::chrono::microseconds, std::function<void()>>;/** Object that stores actions from multiple interleaved scenarios, and data shared across them. * * The Scenario below is used to fill this. */struct Runner{    /** The TxRequestTracker being tested. */    TxRequestTracker txrequest;    /** List of actions to be executed (in order of increasing timestamp). */    std::vector<Action> actions;    /** Which node ids have been assigned already (to prevent reuse). */    std::set<NodeId> peerset;    /** Which txhashes have been assigned already (to prevent reuse). */    std::set<uint256> txhashset;    /** Which (peer, gtxid) combinations are known to be expired. These need to be accumulated here instead of     *  checked directly in the GetRequestable return value to avoid introducing a dependency between the various     *  parallel tests. */    std::multiset<std::pair<NodeId, GenTxid>> expired;};std::chrono::microseconds RandomTime8s() { return std::chrono::microseconds{1 + InsecureRandBits(23)}; }std::chrono::microseconds RandomTime1y() { return std::chrono::microseconds{1 + InsecureRandBits(45)}; }/** A proxy for a Runner that helps build a sequence of consecutive test actions on a TxRequestTracker. * * Each Scenario is a proxy through which actions for the (sequential) execution of various tests are added to a * Runner. The actions from multiple scenarios are then run concurrently, resulting in these tests being performed * against a TxRequestTracker in parallel. Every test has its own unique txhashes and NodeIds which are not * reused in other tests, and thus they should be independent from each other. Running them in parallel however * means that we verify the behavior (w.r.t. one test's txhashes and NodeIds) even when the state of the data * structure is more complicated due to the presence of other tests. */class Scenario{    Runner& m_runner;    std::chrono::microseconds m_now;    std::string m_testname;public:    Scenario(Runner& runner, std::chrono::microseconds starttime) : m_runner(runner), m_now(starttime) {}    /** Set a name for the current test, to give more clear error messages. */    void SetTestName(std::string testname)    {        m_testname = std::move(testname);    }    /** Advance this Scenario's time; this affects the timestamps newly scheduled events get. */    void AdvanceTime(std::chrono::microseconds amount)    {        assert(amount.count() >= 0);        m_now += amount;    }    /** Schedule a ForgetTxHash call at the Scheduler's current time. */    void ForgetTxHash(const uint256& txhash)    {        auto& runner = m_runner;        runner.actions.emplace_back(m_now, [=,&runner]() {            runner.txrequest.ForgetTxHash(txhash);            runner.txrequest.SanityCheck();        });    }    /** Schedule a ReceivedInv call at the Scheduler's current time. */    void ReceivedInv(NodeId peer, const GenTxid& gtxid, bool pref, std::chrono::microseconds reqtime)    {        auto& runner = m_runner;        runner.actions.emplace_back(m_now, [=,&runner]() {            runner.txrequest.ReceivedInv(peer, gtxid, pref, reqtime);            runner.txrequest.SanityCheck();        });    }    /** Schedule a DisconnectedPeer call at the Scheduler's current time. */    void DisconnectedPeer(NodeId peer)    {        auto& runner = m_runner;        runner.actions.emplace_back(m_now, [=,&runner]() {            runner.txrequest.DisconnectedPeer(peer);            runner.txrequest.SanityCheck();        });    }    /** Schedule a RequestedTx call at the Scheduler's current time. */    void RequestedTx(NodeId peer, const uint256& txhash, std::chrono::microseconds exptime)    {        auto& runner = m_runner;        runner.actions.emplace_back(m_now, [=,&runner]() {            runner.txrequest.RequestedTx(peer, txhash, exptime);            runner.txrequest.SanityCheck();        });    }    /** Schedule a ReceivedResponse call at the Scheduler's current time. */    void ReceivedResponse(NodeId peer, const uint256& txhash)    {        auto& runner = m_runner;        runner.actions.emplace_back(m_now, [=,&runner]() {            runner.txrequest.ReceivedResponse(peer, txhash);            runner.txrequest.SanityCheck();        });    }    /** Schedule calls to verify the TxRequestTracker's state at the Scheduler's current time.     *     * @param peer       The peer whose state will be inspected.     * @param expected   The expected return value for GetRequestable(peer)     * @param candidates The expected return value CountCandidates(peer)     * @param inflight   The expected return value CountInFlight(peer)     * @param completed  The expected return value of Count(peer), minus candidates and inflight.     * @param checkname  An arbitrary string to include in error messages, for test identificatrion.     * @param offset     Offset with the current time to use (must be <= 0). This allows simulations of time going     *                   backwards (but note that the ordering of this event only follows the scenario's m_now.     */    void Check(NodeId peer, const std::vector<GenTxid>& expected, size_t candidates, size_t inflight,        size_t completed, const std::string& checkname,        std::chrono::microseconds offset = std::chrono::microseconds{0})    {        const auto comment = m_testname + " " + checkname;        auto& runner = m_runner;        const auto now = m_now;        assert(offset.count() <= 0);        runner.actions.emplace_back(m_now, [=,&runner]() {            std::vector<std::pair<NodeId, GenTxid>> expired_now;            auto ret = runner.txrequest.GetRequestable(peer, now + offset, &expired_now);            for (const auto& entry : expired_now) runner.expired.insert(entry);            runner.txrequest.SanityCheck();            runner.txrequest.PostGetRequestableSanityCheck(now + offset);            size_t total = candidates + inflight + completed;            size_t real_total = runner.txrequest.Count(peer);            size_t real_candidates = runner.txrequest.CountCandidates(peer);            size_t real_inflight = runner.txrequest.CountInFlight(peer);            BOOST_CHECK_MESSAGE(real_total == total, strprintf("[" + comment + "] total %i (%i expected)", real_total, total));            BOOST_CHECK_MESSAGE(real_inflight == inflight, strprintf("[" + comment + "] inflight %i (%i expected)", real_inflight, inflight));            BOOST_CHECK_MESSAGE(real_candidates == candidates, strprintf("[" + comment + "] candidates %i (%i expected)", real_candidates, candidates));            BOOST_CHECK_MESSAGE(ret == expected, "[" + comment + "] mismatching requestables");        });    }    /** Verify that an announcement for gtxid by peer has expired some time before this check is scheduled.     *     * Every expected expiration should be accounted for through exactly one call to this function.     */    void CheckExpired(NodeId peer, GenTxid gtxid)    {        const auto& testname = m_testname;        auto& runner = m_runner;        runner.actions.emplace_back(m_now, [=,&runner]() {            auto it = runner.expired.find(std::pair<NodeId, GenTxid>{peer, gtxid});            BOOST_CHECK_MESSAGE(it != runner.expired.end(), "[" + testname + "] missing expiration");            if (it != runner.expired.end()) runner.expired.erase(it);        });    }    /** Generate a random txhash, whose priorities for certain peers are constrained.     *     * For example, NewTxHash({{p1,p2,p3},{p2,p4,p5}}) will generate a txhash T such that both:     *  - priority(p1,T) > priority(p2,T) > priority(p3,T)     *  - priority(p2,T) > priority(p4,T) > priority(p5,T)     * where priority is the predicted internal TxRequestTracker's priority, assuming all announcements     * are within the same preferredness class.     */    uint256 NewTxHash(const std::vector<std::vector<NodeId>>& orders = {})    {        uint256 ret;        bool ok;        do {            ret = InsecureRand256();            ok = true;            for (const auto& order : orders) {                for (size_t pos = 1; pos < order.size(); ++pos) {                    uint64_t prio_prev = m_runner.txrequest.ComputePriority(ret, order[pos - 1], true);                    uint64_t prio_cur = m_runner.txrequest.ComputePriority(ret, order[pos], true);                    if (prio_prev <= prio_cur) {                        ok = false;                        break;                    }                }                if (!ok) break;            }            if (ok) {                ok = m_runner.txhashset.insert(ret).second;            }        } while(!ok);        return ret;    }    /** Generate a random GenTxid; the txhash follows NewTxHash; the is_wtxid flag is random. */    GenTxid NewGTxid(const std::vector<std::vector<NodeId>>& orders = {})    {        return {InsecureRandBool(), NewTxHash(orders)};    }    /** Generate a new random NodeId to use as peer. The same NodeId is never returned twice     *  (across all Scenarios combined). */    NodeId NewPeer()    {        bool ok;        NodeId ret;        do {            ret = InsecureRandBits(63);            ok = m_runner.peerset.insert(ret).second;        } while(!ok);        return ret;    }    std::chrono::microseconds Now() const { return m_now; }};/** Add to scenario a test with a single tx announced by a single peer. * * config is an integer in [0, 32), which controls which variant of the test is used. */void BuildSingleTest(Scenario& scenario, int config){    auto peer = scenario.NewPeer();    auto gtxid = scenario.NewGTxid();    bool immediate = config & 1;    bool preferred = config & 2;    auto delay = immediate ? NO_TIME : RandomTime8s();    scenario.SetTestName(strprintf("Single(config=%i)", config));    // Receive an announcement, either immediately requestable or delayed.    scenario.ReceivedInv(peer, gtxid, preferred, immediate ? MIN_TIME : scenario.Now() + delay);    if (immediate) {        scenario.Check(peer, {gtxid}, 1, 0, 0, "s1");    } else {        scenario.Check(peer, {}, 1, 0, 0, "s2");        scenario.AdvanceTime(delay - MICROSECOND);        scenario.Check(peer, {}, 1, 0, 0, "s3");        scenario.AdvanceTime(MICROSECOND);        scenario.Check(peer, {gtxid}, 1, 0, 0, "s4");    }    if (config >> 3) { // We'll request the transaction        scenario.AdvanceTime(RandomTime8s());        auto expiry = RandomTime8s();        scenario.Check(peer, {gtxid}, 1, 0, 0, "s5");        scenario.RequestedTx(peer, gtxid.GetHash(), scenario.Now() + expiry);        scenario.Check(peer, {}, 0, 1, 0, "s6");        if ((config >> 3) == 1) { // The request will time out            scenario.AdvanceTime(expiry - MICROSECOND);            scenario.Check(peer, {}, 0, 1, 0, "s7");            scenario.AdvanceTime(MICROSECOND);            scenario.Check(peer, {}, 0, 0, 0, "s8");            scenario.CheckExpired(peer, gtxid);            return;        } else {            scenario.AdvanceTime(std::chrono::microseconds{InsecureRandRange(expiry.count())});            scenario.Check(peer, {}, 0, 1, 0, "s9");            if ((config >> 3) == 3) { // A response will arrive for the transaction                scenario.ReceivedResponse(peer, gtxid.GetHash());                scenario.Check(peer, {}, 0, 0, 0, "s10");                return;            }        }    }    if (config & 4) { // The peer will go offline        scenario.DisconnectedPeer(peer);    } else { // The transaction is no longer needed        scenario.ForgetTxHash(gtxid.GetHash());    }    scenario.Check(peer, {}, 0, 0, 0, "s11");}/** Add to scenario a test with a single tx announced by two peers, to verify the *  right peer is selected for requests. * * config is an integer in [0, 32), which controls which variant of the test is used. */void BuildPriorityTest(Scenario& scenario, int config){    scenario.SetTestName(strprintf("Priority(config=%i)", config));    // Two peers. They will announce in order {peer1, peer2}.    auto peer1 = scenario.NewPeer(), peer2 = scenario.NewPeer();    // Construct a transaction that under random rules would be preferred by peer2 or peer1,    // depending on configuration.    bool prio1 = config & 1;    auto gtxid = prio1 ? scenario.NewGTxid({{peer1, peer2}}) : scenario.NewGTxid({{peer2, peer1}});    bool pref1 = config & 2, pref2 = config & 4;    scenario.ReceivedInv(peer1, gtxid, pref1, MIN_TIME);    scenario.Check(peer1, {gtxid}, 1, 0, 0, "p1");    if (InsecureRandBool()) {        scenario.AdvanceTime(RandomTime8s());        scenario.Check(peer1, {gtxid}, 1, 0, 0, "p2");    }    scenario.ReceivedInv(peer2, gtxid, pref2, MIN_TIME);    bool stage2_prio =        // At this point, peer2 will be given priority if:        // - It is preferred and peer1 is not        (pref2 && !pref1) ||        // - They're in the same preference class,        //   and the randomized priority favors peer2 over peer1.        (pref1 == pref2 && !prio1);    NodeId priopeer = stage2_prio ? peer2 : peer1, otherpeer = stage2_prio ? peer1 : peer2;    scenario.Check(otherpeer, {}, 1, 0, 0, "p3");    scenario.Check(priopeer, {gtxid}, 1, 0, 0, "p4");    if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());    scenario.Check(otherpeer, {}, 1, 0, 0, "p5");    scenario.Check(priopeer, {gtxid}, 1, 0, 0, "p6");    // We possibly request from the selected peer.    if (config & 8) {        scenario.RequestedTx(priopeer, gtxid.GetHash(), MAX_TIME);        scenario.Check(priopeer, {}, 0, 1, 0, "p7");        scenario.Check(otherpeer, {}, 1, 0, 0, "p8");        if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());    }    // The peer which was selected (or requested from) now goes offline, or a NOTFOUND is received from them.    if (config & 16) {        scenario.DisconnectedPeer(priopeer);    } else {        scenario.ReceivedResponse(priopeer, gtxid.GetHash());    }    if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());    scenario.Check(priopeer, {}, 0, 0, !(config & 16), "p8");    scenario.Check(otherpeer, {gtxid}, 1, 0, 0, "p9");    if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());    // Now the other peer goes offline.    scenario.DisconnectedPeer(otherpeer);    if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());    scenario.Check(peer1, {}, 0, 0, 0, "p10");    scenario.Check(peer2, {}, 0, 0, 0, "p11");}/** Add to scenario a randomized test in which N peers announce the same transaction, to verify *  the order in which they are requested. */void BuildBigPriorityTest(Scenario& scenario, int peers){    scenario.SetTestName(strprintf("BigPriority(peers=%i)", peers));    // We will have N peers announce the same transaction.    std::map<NodeId, bool> preferred;    std::vector<NodeId> pref_peers, npref_peers;    int num_pref = InsecureRandRange(peers + 1) ; // Some preferred, ...    int num_npref = peers - num_pref; // some not preferred.    for (int i = 0; i < num_pref; ++i) {        pref_peers.push_back(scenario.NewPeer());        preferred[pref_peers.back()] = true;    }    for (int i = 0; i < num_npref; ++i) {        npref_peers.push_back(scenario.NewPeer());        preferred[npref_peers.back()] = false;    }    // Make a list of all peers, in order of intended request order (concatenation of pref_peers and npref_peers).    std::vector<NodeId> request_order;    for (int i = 0; i < num_pref; ++i) request_order.push_back(pref_peers[i]);    for (int i = 0; i < num_npref; ++i) request_order.push_back(npref_peers[i]);    // Determine the announcement order randomly.    std::vector<NodeId> announce_order = request_order;    Shuffle(announce_order.begin(), announce_order.end(), g_insecure_rand_ctx);    // Find a gtxid whose txhash prioritization is consistent with the required ordering within pref_peers and    // within npref_peers.    auto gtxid = scenario.NewGTxid({pref_peers, npref_peers});    // Decide reqtimes in opposite order of the expected request order. This means that as time passes we expect the    // to-be-requested-from-peer will change every time a subsequent reqtime is passed.    std::map<NodeId, std::chrono::microseconds> reqtimes;    auto reqtime = scenario.Now();    for (int i = peers - 1; i >= 0; --i) {        reqtime += RandomTime8s();        reqtimes[request_order[i]] = reqtime;    }    // Actually announce from all peers simultaneously (but in announce_order).    for (const auto peer : announce_order) {        scenario.ReceivedInv(peer, gtxid, preferred[peer], reqtimes[peer]);    }    for (const auto peer : announce_order) {        scenario.Check(peer, {}, 1, 0, 0, "b1");    }    // Let time pass and observe the to-be-requested-from peer change, from nonpreferred to preferred, and from    // high priority to low priority within each class.    for (int i = peers - 1; i >= 0; --i) {        scenario.AdvanceTime(reqtimes[request_order[i]] - scenario.Now() - MICROSECOND);        scenario.Check(request_order[i], {}, 1, 0, 0, "b2");        scenario.AdvanceTime(MICROSECOND);        scenario.Check(request_order[i], {gtxid}, 1, 0, 0, "b3");    }    // Peers now in random order go offline, or send NOTFOUNDs. At every point in time the new to-be-requested-from    // peer should be the best remaining one, so verify this after every response.    for (int i = 0; i < peers; ++i) {        if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());        const int pos = InsecureRandRange(request_order.size());        const auto peer = request_order[pos];        request_order.erase(request_order.begin() + pos);        if (InsecureRandBool()) {            scenario.DisconnectedPeer(peer);            scenario.Check(peer, {}, 0, 0, 0, "b4");        } else {            scenario.ReceivedResponse(peer, gtxid.GetHash());            scenario.Check(peer, {}, 0, 0, request_order.size() > 0, "b5");        }        if (request_order.size()) {            scenario.Check(request_order[0], {gtxid}, 1, 0, 0, "b6");        }    }    // Everything is gone in the end.    for (const auto peer : announce_order) {        scenario.Check(peer, {}, 0, 0, 0, "b7");    }}/** Add to scenario a test with one peer announcing two transactions, to verify they are *  fetched in announcement order. * *  config is an integer in [0, 4) inclusive, and selects the variant of the test. */void BuildRequestOrderTest(Scenario& scenario, int config){    scenario.SetTestName(strprintf("RequestOrder(config=%i)", config));    auto peer = scenario.NewPeer();    auto gtxid1 = scenario.NewGTxid();    auto gtxid2 = scenario.NewGTxid();    auto reqtime2 = scenario.Now() + RandomTime8s();    auto reqtime1 = reqtime2 + RandomTime8s();    scenario.ReceivedInv(peer, gtxid1, config & 1, reqtime1);    // Simulate time going backwards by giving the second announcement an earlier reqtime.    scenario.ReceivedInv(peer, gtxid2, config & 2, reqtime2);    scenario.AdvanceTime(reqtime2 - MICROSECOND - scenario.Now());    scenario.Check(peer, {}, 2, 0, 0, "o1");    scenario.AdvanceTime(MICROSECOND);    scenario.Check(peer, {gtxid2}, 2, 0, 0, "o2");    scenario.AdvanceTime(reqtime1 - MICROSECOND - scenario.Now());    scenario.Check(peer, {gtxid2}, 2, 0, 0, "o3");    scenario.AdvanceTime(MICROSECOND);    // Even with time going backwards in between announcements, the return value of GetRequestable is in    // announcement order.    scenario.Check(peer, {gtxid1, gtxid2}, 2, 0, 0, "o4");    scenario.DisconnectedPeer(peer);    scenario.Check(peer, {}, 0, 0, 0, "o5");}/** Add to scenario a test that verifies behavior related to both txid and wtxid with the same *  hash being announced. * *  config is an integer in [0, 4) inclusive, and selects the variant of the test used.*/void BuildWtxidTest(Scenario& scenario, int config){    scenario.SetTestName(strprintf("Wtxid(config=%i)", config));    auto peerT = scenario.NewPeer();    auto peerW = scenario.NewPeer();    auto txhash = scenario.NewTxHash();    GenTxid txid{false, txhash};    GenTxid wtxid{true, txhash};    auto reqtimeT = InsecureRandBool() ? MIN_TIME : scenario.Now() + RandomTime8s();    auto reqtimeW = InsecureRandBool() ? MIN_TIME : scenario.Now() + RandomTime8s();    // Announce txid first or wtxid first.    if (config & 1) {        scenario.ReceivedInv(peerT, txid, config & 2, reqtimeT);        if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());        scenario.ReceivedInv(peerW, wtxid, !(config & 2), reqtimeW);    } else {        scenario.ReceivedInv(peerW, wtxid, !(config & 2), reqtimeW);        if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());        scenario.ReceivedInv(peerT, txid, config & 2, reqtimeT);    }    // Let time pass if needed, and check that the preferred announcement (txid or wtxid)    // is correctly to-be-requested (and with the correct wtxidness).    auto max_reqtime = std::max(reqtimeT, reqtimeW);    if (max_reqtime > scenario.Now()) scenario.AdvanceTime(max_reqtime - scenario.Now());    if (config & 2) {        scenario.Check(peerT, {txid}, 1, 0, 0, "w1");        scenario.Check(peerW, {}, 1, 0, 0, "w2");    } else {        scenario.Check(peerT, {}, 1, 0, 0, "w3");        scenario.Check(peerW, {wtxid}, 1, 0, 0, "w4");    }    // Let the preferred announcement be requested. It's not going to be delivered.    auto expiry = RandomTime8s();    if (config & 2) {        scenario.RequestedTx(peerT, txid.GetHash(), scenario.Now() + expiry);        scenario.Check(peerT, {}, 0, 1, 0, "w5");        scenario.Check(peerW, {}, 1, 0, 0, "w6");    } else {        scenario.RequestedTx(peerW, wtxid.GetHash(), scenario.Now() + expiry);        scenario.Check(peerT, {}, 1, 0, 0, "w7");        scenario.Check(peerW, {}, 0, 1, 0, "w8");    }    // After reaching expiration time of the preferred announcement, verify that the    // remaining one is requestable    scenario.AdvanceTime(expiry);    if (config & 2) {        scenario.Check(peerT, {}, 0, 0, 1, "w9");        scenario.Check(peerW, {wtxid}, 1, 0, 0, "w10");        scenario.CheckExpired(peerT, txid);    } else {        scenario.Check(peerT, {txid}, 1, 0, 0, "w11");        scenario.Check(peerW, {}, 0, 0, 1, "w12");        scenario.CheckExpired(peerW, wtxid);    }    // If a good transaction with either that hash as wtxid or txid arrives, both    // announcements are gone.    if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());    scenario.ForgetTxHash(txhash);    scenario.Check(peerT, {}, 0, 0, 0, "w13");    scenario.Check(peerW, {}, 0, 0, 0, "w14");}/** Add to scenario a test that exercises clocks that go backwards. */void BuildTimeBackwardsTest(Scenario& scenario){    auto peer1 = scenario.NewPeer();    auto peer2 = scenario.NewPeer();    auto gtxid = scenario.NewGTxid({{peer1, peer2}});    // Announce from peer2.    auto reqtime = scenario.Now() + RandomTime8s();    scenario.ReceivedInv(peer2, gtxid, true, reqtime);    scenario.Check(peer2, {}, 1, 0, 0, "r1");    scenario.AdvanceTime(reqtime - scenario.Now());    scenario.Check(peer2, {gtxid}, 1, 0, 0, "r2");    // Check that if the clock goes backwards by 1us, the transaction would stop being requested.    scenario.Check(peer2, {}, 1, 0, 0, "r3", -MICROSECOND);    // But it reverts to being requested if time goes forward again.    scenario.Check(peer2, {gtxid}, 1, 0, 0, "r4");    // Announce from peer1.    if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());    scenario.ReceivedInv(peer1, gtxid, true, MAX_TIME);    scenario.Check(peer2, {gtxid}, 1, 0, 0, "r5");    scenario.Check(peer1, {}, 1, 0, 0, "r6");    // Request from peer1.    if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());    auto expiry = scenario.Now() + RandomTime8s();    scenario.RequestedTx(peer1, gtxid.GetHash(), expiry);    scenario.Check(peer1, {}, 0, 1, 0, "r7");    scenario.Check(peer2, {}, 1, 0, 0, "r8");    // Expiration passes.    scenario.AdvanceTime(expiry - scenario.Now());    scenario.Check(peer1, {}, 0, 0, 1, "r9");    scenario.Check(peer2, {gtxid}, 1, 0, 0, "r10"); // Request goes back to peer2.    scenario.CheckExpired(peer1, gtxid);    scenario.Check(peer1, {}, 0, 0, 1, "r11", -MICROSECOND); // Going back does not unexpire.    scenario.Check(peer2, {gtxid}, 1, 0, 0, "r12", -MICROSECOND);    // Peer2 goes offline, meaning no viable announcements remain.    if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());    scenario.DisconnectedPeer(peer2);    scenario.Check(peer1, {}, 0, 0, 0, "r13");    scenario.Check(peer2, {}, 0, 0, 0, "r14");}/** Add to scenario a test that involves RequestedTx() calls for txhashes not returned by GetRequestable. */void BuildWeirdRequestsTest(Scenario& scenario){    auto peer1 = scenario.NewPeer();    auto peer2 = scenario.NewPeer();    auto gtxid1 = scenario.NewGTxid({{peer1, peer2}});    auto gtxid2 = scenario.NewGTxid({{peer2, peer1}});    // Announce gtxid1 by peer1.    scenario.ReceivedInv(peer1, gtxid1, true, MIN_TIME);    scenario.Check(peer1, {gtxid1}, 1, 0, 0, "q1");    // Announce gtxid2 by peer2.    if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());    scenario.ReceivedInv(peer2, gtxid2, true, MIN_TIME);    scenario.Check(peer1, {gtxid1}, 1, 0, 0, "q2");    scenario.Check(peer2, {gtxid2}, 1, 0, 0, "q3");    // We request gtxid2 from *peer1* - no effect.    if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());    scenario.RequestedTx(peer1, gtxid2.GetHash(), MAX_TIME);    scenario.Check(peer1, {gtxid1}, 1, 0, 0, "q4");    scenario.Check(peer2, {gtxid2}, 1, 0, 0, "q5");    // Now request gtxid1 from peer1 - marks it as REQUESTED.    if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());    auto expiryA = scenario.Now() + RandomTime8s();    scenario.RequestedTx(peer1, gtxid1.GetHash(), expiryA);    scenario.Check(peer1, {}, 0, 1, 0, "q6");    scenario.Check(peer2, {gtxid2}, 1, 0, 0, "q7");    // Request it a second time - nothing happens, as it's already REQUESTED.    auto expiryB = expiryA + RandomTime8s();    scenario.RequestedTx(peer1, gtxid1.GetHash(), expiryB);    scenario.Check(peer1, {}, 0, 1, 0, "q8");    scenario.Check(peer2, {gtxid2}, 1, 0, 0, "q9");    // Also announce gtxid1 from peer2 now, so that the txhash isn't forgotten when the peer1 request expires.    scenario.ReceivedInv(peer2, gtxid1, true, MIN_TIME);    scenario.Check(peer1, {}, 0, 1, 0, "q10");    scenario.Check(peer2, {gtxid2}, 2, 0, 0, "q11");    // When reaching expiryA, it expires (not expiryB, which is later).    scenario.AdvanceTime(expiryA - scenario.Now());    scenario.Check(peer1, {}, 0, 0, 1, "q12");    scenario.Check(peer2, {gtxid2, gtxid1}, 2, 0, 0, "q13");    scenario.CheckExpired(peer1, gtxid1);    // Requesting it yet again from peer1 doesn't do anything, as it's already COMPLETED.    if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());    scenario.RequestedTx(peer1, gtxid1.GetHash(), MAX_TIME);    scenario.Check(peer1, {}, 0, 0, 1, "q14");    scenario.Check(peer2, {gtxid2, gtxid1}, 2, 0, 0, "q15");    // Now announce gtxid2 from peer1.    if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());    scenario.ReceivedInv(peer1, gtxid2, true, MIN_TIME);    scenario.Check(peer1, {}, 1, 0, 1, "q16");    scenario.Check(peer2, {gtxid2, gtxid1}, 2, 0, 0, "q17");    // And request it from peer1 (weird as peer2 has the preference).    if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());    scenario.RequestedTx(peer1, gtxid2.GetHash(), MAX_TIME);    scenario.Check(peer1, {}, 0, 1, 1, "q18");    scenario.Check(peer2, {gtxid1}, 2, 0, 0, "q19");    // If peer2 now (normally) requests gtxid2, the existing request by peer1 becomes COMPLETED.    if (InsecureRandBool()) scenario.AdvanceTime(RandomTime8s());    scenario.RequestedTx(peer2, gtxid2.GetHash(), MAX_TIME);    scenario.Check(peer1, {}, 0, 0, 2, "q20");    scenario.Check(peer2, {gtxid1}, 1, 1, 0, "q21");    // If peer2 goes offline, no viable announcements remain.    scenario.DisconnectedPeer(peer2);    scenario.Check(peer1, {}, 0, 0, 0, "q22");    scenario.Check(peer2, {}, 0, 0, 0, "q23");}void TestInterleavedScenarios(){    // Create a list of functions which add tests to scenarios.    std::vector<std::function<void(Scenario&)>> builders;    // Add instances of every test, for every configuration.    for (int n = 0; n < 64; ++n) {        builders.emplace_back([n](Scenario& scenario){ BuildWtxidTest(scenario, n); });        builders.emplace_back([n](Scenario& scenario){ BuildRequestOrderTest(scenario, n & 3); });        builders.emplace_back([n](Scenario& scenario){ BuildSingleTest(scenario, n & 31); });        builders.emplace_back([n](Scenario& scenario){ BuildPriorityTest(scenario, n & 31); });        builders.emplace_back([n](Scenario& scenario){ BuildBigPriorityTest(scenario, (n & 7) + 1); });        builders.emplace_back([](Scenario& scenario){ BuildTimeBackwardsTest(scenario); });        builders.emplace_back([](Scenario& scenario){ BuildWeirdRequestsTest(scenario); });    }    // Randomly shuffle all those functions.    Shuffle(builders.begin(), builders.end(), g_insecure_rand_ctx);    Runner runner;    auto starttime = RandomTime1y();    // Construct many scenarios, and run (up to) 10 randomly-chosen tests consecutively in each.    while (builders.size()) {        // Introduce some variation in the start time of each scenario, so they don't all start off        // concurrently, but get a more random interleaving.        auto scenario_start = starttime + RandomTime8s() + RandomTime8s() + RandomTime8s();        Scenario scenario(runner, scenario_start);        for (int j = 0; builders.size() && j < 10; ++j) {            builders.back()(scenario);            builders.pop_back();        }    }    // Sort all the actions from all those scenarios chronologically, resulting in the actions from    // distinct scenarios to become interleaved. Use stable_sort so that actions from one scenario    // aren't reordered w.r.t. each other.    std::stable_sort(runner.actions.begin(), runner.actions.end(), [](const Action& a1, const Action& a2) {        return a1.first < a2.first;    });    // Run all actions from all scenarios, in order.    for (auto& action : runner.actions) {        action.second();    }    BOOST_CHECK_EQUAL(runner.txrequest.Size(), 0U);    BOOST_CHECK(runner.expired.empty());}}  // namespaceBOOST_AUTO_TEST_CASE(TxRequestTest){    for (int i = 0; i < 5; ++i) {        TestInterleavedScenarios();    }}BOOST_AUTO_TEST_SUITE_END()